A masked gunman shot dead a Dutch priest in the garden of a monastery in the Syrian city of Homs on Monday.
Father Francis van der Lugt, 75, a Jesuit – the same order as Pope Francis – had lived in Syria for decades and had refused to be evacuated with other civilians from the battleground city of Homs.
The gunman's motives were not known and no one immediately claimed responsibility for the killing, which took place in Bustan al-Diwan, a rebel-held district blockaded for more than a year by forces loyal to the Syrian president, Bashar al-Assad.
But the fact that Van der Lugt was attacked in a rebel-held area may underline the fears of many in Syrian Christian and Muslim minorities over the fate of their communities. Over the past year, hardline rebel groups including the al-Qaida-linked Nusra Front have become more influential among opposition fighters in the city.
Van der Lugt's death was first reported by another Homs-based priest, Assad Nayyef, as well as the British-based Syrian Observatory for Human Rights and Syria's state-run Sana news agency.
It appears that Van der Lugt was directly targeted. A single gunman walked into the monastery, entered the garden and shot him in the head, said the Rev Ziad Hillal, a priest who was in the convent when the attacked occurred. "I am truly shocked. A man of peace has been murdered," he said in a phone interview with Vatican Radio.
The Rev Federico Lombardi, a Vatican spokesman, said Van der Lugt, was "a man of peace who with great courage had wanted to remain faithful, in an extremely risky and difficult situation, to the Syrian people to whom he had dedicated for a long time his life and spiritual service."
An activist based in a blockaded rebel area said rebel fighters were shocked by the priest's death. "The man was living with us, eating with us, sleeping with us. He didn't leave, even when the blockade was eased," said Beibars Tilawi. He said the priest was well-liked for his efforts to get the blockade lifted and alleviate widespread suffering and hunger among civilians.
The secretary of the Dutch Jesuit order, Father Jan Stuyt, said the slain priest had been living in Syria since the mid-1960s and was on good terms with members of the country's Muslim majority. "He is like a martyr for the interreligious dialogue," he said.
Van der Lugt repeatedly refused to leave Bustan al-Diwan despite the violence and a series of UN evacuations. A friend who spoke on condition of anonymity because he feared for his safety said Van der Lugt refused to leave until all Christians were evacuated.
It is not clear how many Christians remain trapped in rebel-held parts of Homs. In February there were about 200 Christian families, according to Syrian Red Crescent figures.
Van der Lugt also sought to draw attention to the suffering of civilians in blockaded Homs. "Hunger defeated us! We can see its signs drawn over the faces," he wrote in January on a Syrian Christian Facebook page.
"People are wandering the streets screaming; We are starving, we need food! They stop by the inhabited houses trying to find some food. Hunger breaks the rules and eliminates all moral principles. We are living a scary reality. Human beings turn into wild animals living in the wild."
Albert Abdul-Massih, who worked with Van der Lugt, said the priest held a doctorate in psychiatry and led an austere life. "He was a Christian clergyman but he wasn't conservative," he said. "We learned humanity from him, and he used to love Muslims as much as he loves Christians … He was treating people for free and he was a fluent Arabic speaker."
Abdul-Massih added: "He called me two days ago and told me that he is hopeful that the siege will end soon. His death was a big loss."
Sana blamed "terrorists" for the priest's death but offered no details. The government uses the term for anti-Assad armed rebels.
Another Jesuit priest, Father Paolo Dall'Oglio of Italy, went missing in July after travelling to meet Islamist militants in the eastern city of Raqqa. The city fell into rebel hands in March 2013 and was subsequently taken over by radicals including the al-Qaida breakaway group the Islamic State in Iraq and the Levant.